The present invention refers to an apparatus for separating angel hair, and in particular to a separator of the type having a drum with externally arranged spikes.
During the course of a conventional pneumatic, free-flowing conveyance of bulk material, especially granular plastic material, the formation of filamentous abrasions is frequently observed which is called "angel hair" and may have dimensions of up to one meter length. This angel hair leads to considerable troubles or disturbances during discharge of the bulk material from silos and during sacking and further processing and thus must be removed. One conventional method proposes to screen the bulk material. This method is, however, disadvantageous because of the great dimensions of utilized screens. Another method proposes the use of air separators. However, as it turns out, such air separators could not produce satisfactory degrees of separation.
In separators using a spiked drum, the drum partly immerses in the bulk material flow and is rotated in such a manner that the immersed part of the drum rotates in opposite direction to the bulk material flow so as to allow the spikes to remove angel hair from the bulk material. A drawback of a separator of this type is the difficulty to remove angel hair clinging to the spikes at the circumference of the drum. Proposals to remove angel hair from the spikes by sucking off, blowing off or brushing off were not satisfactory.